Heater



June 16, H. B. HOLTHOUSE 2,286,854

HEATER Filed Sept. 5, 1940 5 Sheets-Sheet l vJlllw 1942- H. B. HOLTHOUSE 2,235,354

HEATER Filed Sept. 5, 1940 5 Sheets-Sheet 2 J1me 1942. H. B. HOLTHOUSE 2,2

HEATER Filed Sept. 5, 1940 5 Sheets-Sheet 3 June 16, 1942.

H. B. HOLTHOUSE HEATER Filed Sept'. 5, 1940 5 Sheets-Sheet 4 June 16, 1942. HOLTHOUSE 2,286,854 HEATER Filed Sept. 5, 1940 5 Sheets-Sheet 5 Patented June 16, 1942 HEATER Harry B. Holthouse, Chicago, Ill., assignor to Galvin Manufacturing Corporation, Chicago, Ill., a corporation of Illinois Application September 5, 1940, Serial No. 355,484

31 Claims.

This invention relates generally to heating devices and in particular to a unit heater of internal combustion type for a mobile craft which is entirely operable independently of the motive engine for such craft.

The prior art vehicle heaters of internal combustion type are of two general classes, namely, suction and pressure heaters. .These heaters are generally operable on a relatively high pressure supply air having suflicient velocity and volume to suitably atomize the fuel to be burned and to maintain a positive flow of the combustible and burning mixture through the heater. This air is usually supplied by utilizing a portion of the engine power, either by direct-connected fan or blower means for the pressure heaters, or by connection with the engine intake manifold for the suction heaters. The heaters, therefore, are dependent for their operation upon a concurrent operation of the engine and are directly responsive in operation to engine running conditions rather than to heater operating or vehicle heating conditions. vDue to the variation in the air as supplied by the engine, the conditions in the combustion chamber are subject to great variation so that burning within the heater is erratic and of highly varying efliciency. Where carburetors and .aspirating means are utilized, the fuel is admitted into the combustion chamberln .proportion to the volume of air supplied. A large quantity of fuel is thus fed into the combustion chamber during a period of light load engine operation while a relatively smaller amount of fuel is admitted to the combustion chamber during a period of heavy load operation. Since the engine load is subject to rapid and frequent changing it is readily apparent that the fuel is burned at a very uneven rate. In some instances combustion may be completely stopped by a too sudden change inthe quantity of fuel admitted to the combustion chamber. This fluctuation of stricted in its operation to limited or critical operating pressures. g

In the case of an automobile which includes the usual battery, generator and other associated electrical equipment, the maximum available current for heater operation is possibly about 7 amperes. It is possible, of course, that a current heavier than 7 amperes might be obtained over some periods of operation, but this heavier current would result in a serious drain on the battery, and in the winter time would seriously interfere with the satisfactory operation and starting of the automobile engine. The operation of an automobile heater entirely from the battery, therefore, requires a complete change in the size and assembly of the parts of the usual suction and pressure heatersto adapt such heaters for operation by the battery. Particularly, the reduction in the size of the air supply means to provide for its electrical operation so reduces its capacity output, as to have heretofore made a batteryoperated car heater of internal combustion type commercially unavailable.

It is an object of this invention, therefore, to provide an improved vehicle heater of unit type which is operable entirely independently of the vehicle engine.

Another object of this invention is to provide an improved automobile heater of internal combustion type, which is of unit assembly and operable entirely by the power from the usual automobile battery.

A further object of this invention is to provide a heater of internal combustion type for the air supply and the consequent surging of fuel in the combustion chamber, effects a noisy burning of the fuel which is annoying and disturbing, especially when the heater is located adjacent to, or in the passenger compartment of the vehicle,

Attempts have been made to overcome these disadvantages of the usual suction and pressure vehicle heaters but these attempts have been thwarted at the outset by the fact that the only power available, apart from the engine power, for operating any of the vehicle equipment is the engine battery. Since this battery is of limited capacity, a heater operable therefrom is re- 5 mobile craft which is efficient and quiet in operation and adapted to be mounted remotely '.vision of a unit heater of internal combustion type which requires only a storage battery and asmall capacity fuel tank for its complete and eflicient operation I Another feature of this invention is found in the provision of a unitautomobile heater of internal combustion type which includes a combustion compartment and a mechanical compart= ment within an enclosing housing structure. The

air recirculated from the passenger compartment is passed through the mechanical compartment prior to its passage through the combustion compartment, whereby to cool the operating devices in the mechanical compartment.

Another feature of this invention is found in the provision of an automobile unit heater of internal combustion type which is mounted outside of the passager compartment of the automobile, but which is completely operated by control mechanism located within the passenger compartment and on the automobile dashboard.

Yet another feature of this invention is found in the provision of an automobile heater of internal combustion type which has a substantially constant heat output, the temperature in the passenger compartment of the automobile being controlled by varying the volume of the heated air admitted to the passenger compartment from the heater.

A further feature of this invention is found in the provision of a heater of internal combustion type having a conditioning unit for treating the fuel prior to its ignition which is preassembled before its installation in the heater, whereby to facilitate the assembly and service work on the heater. 1

Another feature of this invention.is found in the provision of an automobile heater of internal combustion type which is operable entirely independently-of the automobile engine and enclosed by an integrally formed housing structure. The housing is divided into a mechanical .compartment and a combustion compartment, with the mechanical devices being mounted and supported on the dividing wall between the compartments so that ready access is had to all of the mechanical devices immediately on removal of the housmg.

Yet a further feature of this invention is found in the provision of a heater of internal combustion type having a fuel conditioning unit including a heating element with an end portion extending from the unit and having thermostatic means mounted thereon; The thermostat is operable in direct response to the temperature condition of the heating element to control its operation whereby to retain the temperature of the heating element substantially'constant by the practical elimination of any time lag in such control.

Yet anotherfeature of this invention is found in the provision of a heater of internal combustion type having a fuel system including a pulsating type pump and a fuel nozzle which has a cavity formed therein between the inlet and outlet thereof, the cavity being of a large volume relative to the injector discharge passage whereby to cushion and substantially eliminate any pulsating effects of the pump in the nozzle discharge passage.

A further feature of this invention is found in the provision of a combustion chamber for a heater of internal combustion type which is of substantially cylindrical shape and includes a body and fin portions of integral construction. A partition member engageable with the fins and positioned within the chamber body is of a construction to divide the chamber into a plurality of connected axially extending passages, whereby to provide a chamber of elongated construction.

Another feature of this invention is the provision of a heater of internal combustion type having a fuel system which includes a pulsating type pump and a device for metering the fuel flow from the pump in a manner to provide for a substantially uniform rate of fio'w in the system.

Further objects, features and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawings in which:

Fig. 1 isa view in perspective of the complet heater assembly; I

Fig, 2 is a detail view in perspective of the partition member for dividing the heater combustion chamber into a plurality of axially extending passages;

Fig. 3 is a sectional view as seen along the line '33 in Fig. 1, the showing of the combustion chamber being somewhat of a developed view; Fig. 4 is a sectional detail view of the fuel conditioning unit illustrated in Fig. 3;

Fig. 4a shows the fuel conditioning unitof Fig. 4 with a modified thermostatic unit;

Fig. 5 is a view as seen along the line 5-5 in Fig. 4;

Fig. 6 is a modified form of the conditioning unit illustrated in Fig. 4;

r Fig. 7 is a sectional detail view of the fuel metering device which is shown diagrammatically in Figs. 1 and 3;

Fig. 8 is an end view of the heater unit looking at the fuel conditioning unit, with portions thereof being removed for the purpose of clarity;

Fig. 9 is an end view of the combustion chamber showing the assembly arrangement therein of the dividing member shown in Fig. 2;

Fig. 10 illustrates diagrammatically a control circuit for the heater assembly including the fuel conditioning unit of Fig. 4;

Fig. 11 is illustrated similarly to Fig. 10, but is applicable to themodified fuel conditioning unit shown in Fig.7;

, Fig. 12 is a plan view of the controlunit for the heater;

Fig. 13 is a sectional view as seen along the line |3-|3 in Fig. 12;

Fig. 14 is an elevational view of the control unit looking toward the right as viewed in Figs. 12 and 13, and

Fig. 15 is a fragmentary side view of an automobile with portions thereof removed to show the mounting of the heater and heater control unit relative to the automobile passenger compartment.

The invention is illustrated as applied to an automobile, the heater unit being completely enclosed and provided with-suitable leads for connection of its fuel system with the usual .automobile gas tank and connection of its control circuit with the usual car battery. It is contemplated that the heater be entirely operable independently of the automobile engine and operated entirely by the electrical power from the usual car battery. Since the electrical power available from the usual car battery is relatively small the motor in the heater, which is common to the air supply and air recirculating means, is of a size to operate on about 5 amperes of cur-. rent. This current rating is far below the average amperage rating of the normal car battery and well within all practical factors of safety for 7' heater current consumption. The use of a 5 ampere motor for operating the air and fuel supply means produces an effective operating air pressure in the heater of about to A" of water. Fuel cannot be properly atomized by an air pressure of this order so that the air and fuel like material. to form a series of alternate peripheral sections progressively burning the combustible mixture over substantially the complete length of a combustion chamber of elongated construction. The air from the automobile passenger compartment is circuated directly about the combustion chamber, withthe temperature within the compartment being controlled by varying the amount of heated air entering the passenger compartment from the' heater.

Referring to Figs. 1 and 3 of the drawings the heater is seen to include a substantially centrally disposed longitudinally extending frame member 2| having avertically extending wall portion 22 which divides the heater into a mechanical compartment 23 and a combustion compartment 24. Compartment 24 accommodates a combustion chamber 21 which is substantially coextensive in length" with the compartment 24 and is secured to one side of the vertical wall 22 between laterally extending wall portions 28. Wall portion 22 is formed with cut or punched out ear portions 29 and 26', which extend substantially normal to the wall and into the mechanical compartment 23.

A fuel pump 3|, which may be of solenoid type, is mounted on an ear portion 26'. A fuel metering device, indicated at 32, is in the fuel'line 33 which connects the pump with a fuel nozzle 34 mounted in a fuel conditioning unit 36, to be later ness of a peripheral section 46. The outer ends 55 of the fins 45 are thus closed while their inner ends 43 are open and readily separable. Positioned within the body portion 21a is a partition member 52 which is of substantially cross-shape and comprised of dovetailed members 53 and 54 which are of a width substantially equal to the diameter of the combustion chamber 21. As

' shown in Fig. 2, plate 53 is .of substantially recexplained. Operation of the pump is controlled,

being arranged in the-compartment 24, so that the removal of the housing member 36 completely opens the compartment 23 for access to the motor 39, fuel pump 3|, metering device 32,,

and air fans 4| and 42;

Plate 44, as is best seen in Fig. 3, forms part of a passage 46 which extends about the combustion. chamber 21. The recirculated air is drawn into .the mechanical compartment 23 through an aperture 41 (Fig. 1) formed in a housing member 25, the air from the compartment being discharged by the fan into the passage 46 and outwardly from the unit through the air-header 50 and discharge outlet 48. Supply air for combustion enters the heater through the inlet 6! formed in the housing 30 and is discharged by the fan 4| into an air supply chamber 66. to be explained.

The combustion chamber 21 (Figs. 1 and 9) is of substantially cylindrical shape and includes a body member 21a of unit construction and formed from a single piece of flat sheet steel or suitable The member 21a is press shaped 46 and axially extending radial fin elements 45, a fin 45 being arranged between adjacent peripheral sections 46. As is clearly seen in Fig. 9, each fin 45 is. bent double so as to have twice the thicktangular form and slightly less in length than the plate 54. Plate 54 is also of substantially rectangular shape and isformed with a projection 56 at one end thereof which lies to one side of the plane of the plates 53 when the plates 53 and 54 are in their dovetailed engagement.

In arranging the partition member 52 within stantially coextensive in length with the body portion 21a and upon its being completely extended therethrough, the inner ends 46 of all of the fins are rigidly secured together, as by welding or like means. The member 52 and the body portion 21a are thus assembled into a rigid and integral unit. The chamber 21 is closed at its ends by plates 6| and 62 which are also welded to the body portion 21a. 7 J

The partition member 52 is thus seen to provide for a series of connected passages within the body portion 21a which have a combined length of. four times that of the body portion 21a. An inlet and an outlet for the elongated passage is obtained by the' apertures '63 and 64, respectively, formed in the end plate 62. Thus as indicated'by the arrows in Figs. 2 and 3 the continuity of the passage from the inlet 63 is through the quadrants 5|a, 5| b, 5|c and 5| d, in that order,

and outwardly through the combustion chamber outlet 64. A cylindrical shell or sleeve 65 positioned;about the fin ends 55 encloses the body portion 21a to form the annular passage 46, which is divided radially by the fins 45. It is readily apparent that partition members may be readily provided to form a varying number of longitudinal passages in the combustion chamber 21, the size of the chamber 21 and hence the size of the passages being controlling in the number desired.

The inlet 63 of the combustion chamber is of somewhat smaller diameter than the chamber passage 5la and is provided with an inwardly extending flange portion 60 for the mounting thereon of the fuel conditioning unit 36. A part of the unit 36 (Figs. 3 and 4) is located within the air supply chamber 66, which is formed at one end of the combustion chamber 21 by the end plate 62, the partition plate 44 and the housing members 25 and 30. The unit 36 includes an air and fuel mixing chamber 68 and an equalizing chamber 69, which are formed within a housing 7| of substantially cylindrical shape. As viewed inFig. 4 the upper side of the housing 1| is of substantially straight contour, while the lower side is of substantially stepped contour near the closed housing end 12. The stepped or wall portion 13 is located substantially opposite the air and fuel inlet 14 to the chamber 63. Inlet I4 is formed with a suitable mounting portion for the fuel nozzle 34, which was previously mentioned, the air for combustion being-admitted into the mixing chamber through apertures arranged about the inlet M.

The nozzle 34 is of substantially cylindrical form and is provided with a body portion 34a having a Venturi passage 11 therein, and a top portion 18. The top portion 18 is provided with a cavity 19 which is connected with the fuel line 33 at the nozzle inlet 8| and is in communication with the venturi 11 through a discharge passage 82. In pumps which operate to produce pulsations in the fuel line, such as the solenoid pump 3 I, the

fuel in the supply line is discharged in waves rather than in a steady or uniform'flow. The

. cavity 1!! acts to cushion these fuel surges caused by the pump by virtue of the fact that the air pocket which is formed above the cavity, during normal operation of the fuel system, is compressed to absorb the fuel pulsations. To provide for the greatest uniformity in the rate of fuel fiow, the volume of the cavity 19 is rather large relative to the volume of the discharge passage 82. In one commercial embodiment of the invention the cavity has a volume of about .061 cubic inch while the volume of the discharge passage is .000119 cubic inch. In this embodiment the diameter of the passage is about .02 of an inch and the length about of an inch, the small diameter opening serving further to cushion the fuel pulsations caused by the pump 3|. This construction of the nozzle 34 serves to reduce the pump pulsating effects in the discharge passage to a minimum so that the fuel flow in the passage 82 and through the venturi TI is substantially steady and even.

The quantity of fuel passing through the nozzle 34 and hence admitted to the unit 36, is regulated by the fuel metering device 32, which is shown in detail in Fig. 7. A body member 83 of sleeve form is threadably connected at one end to the pump 3|, a plug 84 being threadably secured to the opposite end thereof for connection with the fuel supply line 33. The body member 83 is of a length to provide for the formation therein between the pump 3i and the plug 84 of a cavity 86 which is filled with a fuel filter of felt or other suitable like material. An air dome or cap 85 is threadably secured in the member 83 in fluid communication with the cavity 86. Dome 85 serves to cushion or absorb any fuel surges'in the cavity 86, in a well known manner, so as to effect a more even flow of the fuel through the device 32. The fuel line 33 between the metering element 32 and the nozzle 34 is of a length of about 9 inches. Extended over approximately of this length and in the line 33 is a core member 81 which may be provided in wool yarn, glass, wire or the like. The member 81 functions to meter the fuel by virtue of its increasing the resistance to the flow of the fuel in the line 33 and effecting somewhat of a capillary or surface-tension action between the surfaces of the core member 81 and the fuel pipe or line 33. This action provides for a definite creeping of the fuel through the metering device irrespective of any applied pump pressure; the pump pressure serving to accelerate this creeping action. Increasing the diametenof the core member decreases the fuel flow through the line, but increases the capillary flow of the fuel by virtue of the increase in the surface of the core member. Thus it has been found that a glass core comprised of a plurality of fine strands produces a greater flow by surface action or tension than a single strand of the same diameter. The same general relation was also found to be true in the.

that a variation in both the diameter and the length of the core member 81 relative to the fuel line 33 effects a corresponding variation in the capillary characteristics also varies as betweenthe different materials which might be used for the core 81, so that a relatively wide range of metering can be obtained by the metering device 32. It is to be noted also that the restricted fuel line in the metering device serves further to decrease the pulsating effects of the pump 3| in that portion of the fuel line between the metering device and the unit 36.

The mixing chamber 68 and the equalizing chamber 69 are separated from each other by a cup-shaped member 88 which is arranged in the unit housing II, the closed end 89 .of the cup member being positioned near the stepped wall portion 13. The closed end or partition wall 89, is formed over about its upper portion with a plurality of apertures 9|, the lower third of the partition being imperforate so that communication between the chambers 68 and 69 is only through the apertures 9|. The inclined wall 13 is directed away from the partition wall 89 to form a trough or pocket 92 at the bottom of the unit 36, as viewed in Fig. 4, between the wall I3 and the imperforate bottom portion of the partition 89, for a purpose to be later explained. The open end of the cup member 88 is in abutting engagement with a heat insulating plate 93, which is positioned over the outlet 16; but within the unit 36. An annular rim or flange 94 thus projex s outwardly from the unit 36 beyond the platef93.

As shown in Fig. 5 the plate 93 is formed with a plurality of apertures 96 which are arranged in substantially a complete circle near its periph-- eral edge. A heating element 91 is mounted in the plate 93 near the upper portion thereof. The element 91 is of substantially cylindrical shape and extends axially outwardly from the unit 36, and is formed at its free end with an enlarged heating portion 98. The element 91 functions as a hot spot to continue the burning of an already ignited mixture, as will be later explained.

It is contemplated in the present invention that the ignition means for the combustible'mixture be included as part of .a combination preheating and igniting element or unit 99,'which comprises a resistance coil I 0| arranged in an insulating tube I02, which in turn is mounted in a copper tubular sleeve I03. The element 99 extends longitudinally through the conditioning unit 36, one

end I84 thereof extending outwardly from the outlet 76 and an opposite end I extending outwardly from the closed end 12 of theunit-housing 1|. Support of the heating element inthe unit is accomplished by its extension through the plates 89 and 93 and the closed housing end I2, with the housing end and the partition wall 89 being arranged in thermal relation therewith. That portion of the heating element inthe chambers 68 and 69 functionsto heat the fuel conditioning unit 36, the unit housing 1! and the cup member 88 being provided in copper .or other high heat conducting material to assure a rapid and uniform distribution of the heat throughoutthe unit. The chamber 69, which is defined by the partition walls 89 and 93, is filled with a copper wool or like material having high heat conducting characteristics so that the heat from the heating element 99 is conducted into all portions equalizing chamber 69 is thus continuously heated during its passage therethrough, as will beex-- plained, The element 99, therefore, does not operate as a hot spot," but operates rather to heat the mixing and equalizing chambers and their surrounding walls to a substantially uniform temperature, with the variation of the temperature within the chambers and their surrounding walls and element 99, being about 10 degrees Fahrenheit.

A controlled heating of the unit 36 for advantageously conditioning or vaporizing the fuel therein is accomplished by m ans of a thermal switch unit I06 (Fig. 4) which is responsive to the heat of the heating element 99 and acts in part to regulate the operation of such heating means. The unit I06 is mounted on, but electrioally insulated from, the heating element end I05 and in its normalassembly within the heater 20 extends into the air supply chamber 66 (Fig. 3). The unit is comprised of bi-metal contact arms I01 and I08 and associated spring contact arms I09 and H0, respectively. As shown in Fig. 8, the arms I'I--IIO, inclusive, are of substantially flat form and are apertured, as at I II, (Fig. 4) so as to be mounted about an insulated clamping sleeve II4, suitable collars II3 of insulating material being arranged between the arms for spacing purposes. The sleeve II4 with the arms I0I--IIO and spacing collars II3 thereon is then mounted as a unit on the insulating sleeve I2 which in turn is mounted on the heating element 99, as is clearly indicated in Fig. 4. The bi-metal arms I01 and I00 aremovable independently of each other and are adapted for movement at different temperatures, bi-metal switch I08I I0 being in a normally closed position and arranged in the electrical circuit of the heating element 99, and the bi-metal switch I0I-I09 being normally open and ar-- ranged in the electrical circuit of the fuel pump 3| Included with the thermostatic unit I06 and adjacent the contact arm I 09 is a bracket member I I6 having an angular end portion III. The

spring conductor I20 electrically connecting bi-f and 4) which is attached to the frame plate 44.

and arranged to frictionally engage the knob II 9 contact C of the arm B, and suitably tensioned to follow the arm B during a part of its movement toward arm I09, as will be explained. The mounting of the unit I 06' on the heater 99 is similar in all respects to that of the unit I06. A bracket III of substantially right angle shape is arranged adjacent the contact arm I09, with the end portion II'Ia. thereof being suitably recessed to straddle the supporting rim I4 for the fuel nozzle 34. This arrangement of the bracket III' serves to eliminate any tendency of the unit I06 to rotate about the heating element '99. The unit 36 for either of the thermostatic the end I04 of the heating element is located at the combustion chamber inlet 63, the projection of heat from this end acting to ignite the fuel mixture entering the chamber. The heat thus projected isconfined at the end I04 by the heat insulating partition 93, the degree of ignition heat being determined essentially by the watt input to the resistance IOI and being contemplated in the present invention to be about 1800 F. The temperature in the mixing and equalizing chamber, however, is at all times less than that which would eifect an. ignition or burning of the fuel within such chambers, and is contemplated to be about 300 F. Thus although the ignition temperature of the fuel is about 1800 F., the partition 93 substantially prevents this high heat from being transferred into the chambers of the fuel conditioning unit '36, so that an 1800" F. temperature on one side -of the plate 93 occurs simultaneously with a temperature of only 300 F. on the opposite side thereof. This large diiference between the optimum' temperature within the vaporizing or fuel conditioning unit 36 and the ignition temperaturewithin the combustion chamber 21 posi- I tively eliminates any burning of the fuel within formed on the portion I6 of the nozzle 34. It is to be noted that the nozzle is also held in its supported position in the unit 36 by the spring V bracket II0.

A modified form of the thermostatic unit I06 for the fuel conditioning unit 36 is shown in Fig. 4a. The unit I06 includes a single bimetallic arm B having contacts C and C arranged on opposite sides thereof for engagement with contact arms I09 and IIO'- respectively. Contact arm I09 is arranged in the electrical circuit of the pump 3I and motor 39 and is normally separated from the contact C on bi-metal arm B. .The arm IIO forms part of the circuit for the heater 90 and normally is in contact with the conditioning unit 36.

The heating element 99 is energized by its connection with a suitable electrical source such as the car battery II5 (Fig. 10), the circuit from the battery including conductor I2 I, a main control switch I22, conductors I23 and I24, bi-metal switch I00--IIO and conductor I20; the circuit being completed to ground by connection of the resistance wire IN to the copper tubing I03 at the igniter end I04 of the heatingelement. Conductors I2I and. I23 and control switch I22 are also common to the circuit of the fuel pump 3I, which further includes bi-metal switch I0II09, conductor I21, the breaker assembly 31 and a conductor I28. The motor 39 is connected di rectly to the battery II5 through conductors I2I and I23, and the control switch I22.

Operation of the heatr 20 is started by closing the main switch I22 which simultaneously operates the heating element 99 and fans 4| and 42, the circuit of thefuel pump 3I being opened by the normally open bi-metal switch I0I -I09 (Fig. 10). When the heating element 99 is heated to a temperature of about 75 F., the bi-metal arm I0'I moves into contact with the arm I09 to close the circuit of the fuel pump 3I. The pump circuit is thus closed only whenthe element 99 is in an operable condition. The air and fuel supplied-to the chamber 68 by the fan H and fuel pump 3| contacts the inclined wall portion I3 and that portion of the heater element 99 within the chamber 58. Since the wall I3 is at substantially the same temperature as the heating element 99, the fuel is partially vaporized by such contact so as to be intimately and thoroughly mixed with the air. The resultant mixture is forced through the apertures 9I in the partition wall 89 and then into the equalizing chamber 69 by the effective operating pressure produced in the air supply chamber 66 by the air supply fan 4|. The mixture from the equalizing chamber passes through the apertures 96 in the insulating plate partition 93 into the combustion chamber fuel for efficient combustion at low pressures, the

bi-metal arm I09 moves out of contact with the arm IIO to stop the operation of the heating element; the fans II and 42 and fuel pump 3i continuing in operation. Since the variation of the temperatures between the chambers 68 and 69, and the heating element 99, as was previously mentioned, is only about 10 F., it is to be understood-that this optimum temperature is also substantially the temperature of the chambers. However, since the thermostat I06 is responsive directly to the temperature condition of the heating element, the element only will be referred to in the following description. At this operating temperature of 200 F., the fuel contacting the element 99 and the wall portion 13 is substantially immediately vaporized by the heat in these parts, the angular inclination ofv the wall 13 deflecting the mixture against the partition wall 89 to substantially completely vaporize all of the fuel supplied to the chamber 68. Any raw or free fuel particles which are not immediately vaporized in this manner drop to the bottom of the chamber 68 and into the fuel cavity or trough 92. Since the cavity is formed by the heated Wall I3 and partition 89 and further has the heating element 99 extending across the top thereof; the raw fuel thus collected is additionally heated. The collected fuel 'is also exposed to the warm supply air circulating within the chamber 68 whereby to facilitate its passage into he chamber 69 in a vaporous form. All unmixed or free fuel particles are thus retained in the chamber 69 until they are properly conditioned sothat all of the fuel passing into the chamber 69 is in a vaporous form.

The vaporous form of the mixture is maintained in the chamber 69 by virtue of the heated copper wool in the chamber, the wool acting fur ther to diffuse all portions of the mixture to produce a mixture of substantially uniform fuel density. Since the mixture in the chamber 68 is in somewhat of a turbulent state, the structure of the chamber 69 acts further to equalize the velocity flow and pressure of the mixture over the entire transverse cross-sectional area thereof.

The fuel mixture entering the chamber 21 tions, so that burning of the fuel proceeds both quietly and efficiently. v

The above described operating condition of the heater continues until the temperature of the heating portion of the element 99 falls below about 200 F., at which temperature the bimetal arm I08 moves into contact with the arm I I0 to again energize the'heating element 99. When the temperature of the heating element and hence of the chamber 68 is again increased to about 200 F., the bi-metal arm I08 breaks away from the contact arm IIO to again open the circuit of the heating element 99. This controlled operation of the unit 36 continues during normal operation of the heater, which operation is stopped by opening the switch I22.

During the normal operation of the heater a portion of the heat from the combustion chamber 21 is transmitted through the walls of the fuel conditioning unit 36 and also through the heater element 99 tothe mixing chamber 68 and equalizing chamber 69.. This transfer of heat decreases the .dissipation of heat from these chambers, and particularly that loss of heat which occurs in the chamber 68 by virtue of the vaporization of the fuel therein. In this manner the conducted heat-functions as a saving device to reduce a frequent and prolonged operation of the bi-metal switch I08I I0 in its control of the heating element 99.

The location of the thermal unit I06 on the element end I05 substantially eliminates any drifting of the temperature in the mixing chamber. This desired condition is accomplished because the thermal unit is in substantially direct thermal connection with the heating element. and operates substantially immediately to control the heater element. The time lag between the response of the unit I06 to the temperature condition of the element 99 and its control of the operation of the element is thus reduced to a minimum so that a practically uniform operating temperature occurs in the mixing and equalizing chambers. It is to be understood, however, that the energization of the heating element 99 by the thermal unit I06 does not indicate any failure of combustion in the chamber 21. The fuel is processed or conditioned entirely independently of the burning conditions in the combustion chamber 21 and the bi-metal switch I06 operates to energize the heating element only in response to the temperature conditions in the mixing chamber GIL-which as previously mentioned, is of substantially the same temperature as the heating element.

The mixture from the mixing chamber 69 is retained in a vaporous form for burning in the combustion chamber 21 by virtue of the heat transmitted thereto from the wool in the chamber 69. However, in the passage of any flame or spark from the combustion chamber into the equalizing chamber 69, the relative temperature difference between the combustion chamber and the equalizing chamber is such that heat is taken up by the copper wool so that the flame or spark is extinguished by the reduction of its temperature below the ignition point of the mixture. The equalizing chamber 59 thus acts to prevent any occurrence of flashback in the combustion chamber 21 from entering the mixing chamber 68.

- To assure a positive and immediate burning of the fuel at all times of heater operation, it is contemplated that the air and fuel be supplied to the mixing chamber 68 in relative proportions to provide a mixture rich in fuel. Although a rich mixture is readily ignited it is inefficiently burned unless additional air is mixed with the rich fuel portions remaining after the initial ignition of the mixture. A portion of this additional air is admitted into the combustion chamber directly from the air supply chamber 66 through apertures 63a formed in the end plate 62 and about the combustion chamber inlet 63 (Figs. 3 and 8). Since the air in the supply cham ber 66 is under the pressure of the fan 4|, it is readily apparent that the air moves through the apertures 63a with an initial velocity. By virtue of the rim portion 94 at the fuel conditioning outlet 16, the air flow through the apertures 63a is kept away from the mixture leaving the unit 36, until after ignition thereof. The initially rich mixture is thus first'ig'nited prior to the addition thereto of additional free air.

The air from the ports 63a, however, does not provide for a complete burning of the mixture. Because of the elongated construction of the combustion chamber and the low velocity of the air at the ports 15 and63a, a progressive burning of the mixture serves to move the flame and mixture through the chamber 21. As this burning mixture passes along the hot spot 91, the heat therefrom acts to immediately intensify the burning of the mixture so that a hot blue flame is projected through. the center of the chamber passage to progressively mix with and burn the rich fuel mixture extending thereabout. This progressive burning of the initially rich fuel mixture is facilitated by admitting additional air into the passage 5Ic through the port 62a, which also opens into the air supply chamber 66. A tubeT at the aperture 62a extends within the quadrant 5Ic a distance at least beyond the communicating passage between quadrants 5") and 51c to direct the ilow of the air therethrough only into the quadrant 5| 0. It is thus seen that a hotfiame through the chamber 21 coacts with closing of the heater circuit should continue to.

additional or supplementary air to progressively burn to completion an initially rich fuel mixture,

the burningbeing extended over substantially the entire length of the combustion chamber.

The heating element or hot spot .91 by virtue of the loose terminology applicable "thereto may be referred to as a reigniter. However, in function, one theory propounded is that the element 91 gasifies the originally-vaporous fuel mixture which passes adjacent thereto and that this gasification increases its rate of burning and effects an expansion thereof which acts toaccelerate the flow of the mixture through the chamber 21. Gasification of the vaporous mixture then proceeds progressively, additional air being added to assure sufficient air for an eflicient and complete burning of the mixture.

A final portion of air is admitted into the combustion chamber through a tube 64a, which is mounted in the end plate 62 and extends into the'passage Sld. Tube 64a is in communication with the supply chamber 66; the extending end 64b being of hook shape and bent in the direc-. tion of mixture flow.

It is contemplated that the tube .extend about three inches into-the passage Sld, which is about ten inches long. This short tube length permits but little space for any additional burning of the mixture, the primary function of the air from the tube 64a being to cool the exhaust gases whereby to reduce the back pressures in the passages Sin-Sid, which are of relatively small section. It is to be noted that the air through the apertures 63, tube T and tube 64a is directed in the direction of mixture flow to aid the flow through the chamber 21.

The operation of the heater utilizing the thermostatic unit I06 is more clearly understood with reference to Fig. 4a and in particular to the control circuit which is diagrammatically illustrated therein. Closing of the main switch 20| closes the energizing circuit for the heating element which from the battery H6 includes conductor 202, bi-metal arm B, contact arm I I0, resistance coil MI and ground connection 203.

When the bi-metal arm B is heated to about F. by the element 99 it moves into contact with the arm I09 whereby to energize the circuits for the pump 3| and motor 39. The pump circuit is comprised of conductor 2'02, arms B and I09, conductor 204, breaker assembly 31 and ground connection 206, the motor being connected to the conductor,20| and grounded at 201. -The arm H0 is normally tensioned to follow the bimetal arm 13 until the heater element 99 and hence chamber 68 reaches a temperature of about 200 F. At this time contact C breaks away from arm H0 whereby to open the heater circuit, the pump 3| and motor 39 continuing in operation. Should the temperature of the chamber 68 fall below about 200 F. bi-metal arm B will remake contact witharm H0 to again energize the heater 99. If for any reason, such use failure of the heating element 99 to become heated, the temperature of the chamber 68 after decrease, bi-metal arm B will continue its movement toward the right, as viewed in Fig. 4a, un-

til contact with arm I09 is broken, thereby stopping the operation of the pump 3| and fan 39, Air and fuel is thus supplied to the unit 36 only when the heating unit 99 is in an operable condition. Under normal operating conditions, however, the bi-metal arm B is in contact with both arms I09 and H0 for a temperature range of the chamber 68 of from about 80 F. to 200 F. In view of the foregoing detailed description of the heater operation with reference to. Figs. 4 and 10 its complete'operation with the thermostatic unit I06 is believed to be entirely clear from the above description of the circuit diagram in Fig. 4a.

A modified form of' the fuel conditioning unit 36 shown in Fig; 4, is illustrated in Fig. 6, a heating element 99' and an igniter element I 04', being indicated as physically independent. Since the remainder of the unit 36' is substantially similar in construction to the unit 36, similar numerals of reference shall be used to designate similar parts. The element 99' is supported in the wall 89 and closed end of the unit housing- H. the assembly of the thermostat I06 and nozzle 34 (not shown) relative to the element 99' being identical with the assembly of Fig. 4. Heat insulating plate 99' is formed with peripherally extending apertures 96', the element 9'1.

extending only through the chambers 68 and 69 andnot being supported in the plate 93. The heat generated by the element 99 is,'therefore, utilized entirely in heating the conditioning unit chambers 68 and 69, Although the heater element 99' is thermally connected with the housing 1| and member 88 it is electrically insulated therefrom so that the coppertubing Ill may be utilized as an electrical conductor, as will be explained. Igniter I04 is located within the passage 5| a of the combustion chamber 21 in a position relative to the outlet 16 of theunit 86' and to the end 98 of the heating element 81 which is substantially the same as that of the end I04 of the combined heating and igniting element 99 of Fig. 4.

An operating circuit for the heater 20 utilizing the conditioning unit 36' of Fig. 6, is shown in Fig. 11. The element 99' is electrically connected with the car battery II5, the operating circuit from the battery including conductor I2I, main control switch I22, and conductor I3I whichis connected directly to the resistance coil IOI' of the element. Since the coil IN is connected directly to the copper tubing I03 the tubing is used as aconductor for connecting the coil IOI' with the bi-metal switch I08I I0. The circuit is completed by connection of the switch I08--I I through conductor I32 with the igniter I04 which is grounded at I33. It is thus seen that the heating element 99 and igniter I04 are connected in series so as to be operable concurrently on closing of the bi-metal switch III8-IIO. The motor 39 is connected directly to the battery II5 through conductors I2I and I23 and the control switch I22. The motor circuit is also common to the circuit of the fuel pump 3I which includes further conductor I34, breaker assembly 31, conductor I36, and the bi-metal switch I01-I09. On closing of the main switch I22, the heating element 99' and igniter I04 are energized simultaneously. similarly to the energization of the entire heating element 99. In one commercial embodiment of this structure it is contemplated that #19 wire be used in the heating element 99', and #20 wire in the igniter I04. The igniter will thus heat up to a higher temperature than the heating element. Since the remainder of the control circuit and the operation the thermostatic unit I06 is identical in all respects with the operation of the control circuit and operation of the heater 20 previously described in connection with Fig. 10, a further description of the operation of the circuit of Fig. 11 is believed to beunne'eessary.

One commercial arrangement of the heater 20 showing its application to the heating of an automobile is illustrated in Fig. 15, the heater 20 being shown as mounted below the automobile passenger compartment I31 and under the front seat I38 therein. The recirculated air inlet 41 and outlet 48 are located on opposite sides of a. baflle directing plate I39 to eliminate any short circuiting of therecirculated air between the openings 41 and 48 and to provide for a circulation of the air to all portions of the passenger compartment, as indicated by the arrows.

Operating control of the heater is accomplished by a control unit I which includes the main switch I22 of the heater control circuit.

The control unit is provided with a housing I42 of box shape, mounted on the dashboard I 43 and having a front wall I44 of arcuate contour formed with a laterally extending slot I46 therein. (Figs. 12 and 14). -A control lever I41 of substantially T-shape'is pivotally supported at I48 intermediate the ends of its cross-member I49. The end I5I of cross-member I49 is directly engageable with the control switch I22, which This con The end 56 of the cross member I49 is operatively connected, as by a Bowden wire I51 to a bypass valve I58 (Figs. 1, 3, and 15), which is mounted on the housing member 30. The valve includes a body portion 'I6I of substantially bell shape, which is secured at its open end to the member 30 and is formed in the sides thereof movement of the wire is also accomplished by manipulation of the control lever I41 about its pivotal support and in the slot I46.

With the lever I41 in the full line position indicated in Fig. 12, the valve I63 is in the closed position shown in Fig. 3, and the switch at the open position shown best in Fig. 13. By suitable indicia IE5 (Fig. 14) positioned above the slot I46, it is seen that this full line position of the lever represents the off condition of the heater. On initial movement of the lever to its dotted line position, shown in Fig. 12, or to the right as viewed in Fig. 14, the armend I5I is withdrawn from its engagement with the switch I22 to permit closing of the contact arms I53 and I54 and a consequent operation of the heater. This starting position of heater operation designates the maximum volume of heated air which is supplied to the automobile compartment I31, as indicated on the indicia I66; On a continued moving of the lever I41, the switch I22 remains unaffected, but movement of the arm end I56 I draws on the wire I51 to move the valve portion I63 progressively farther away from the opening I64 in the housing member 30. The heated air from'the header portion 50, which would normally pass through the heater outlet 48 into the compartment I31, is thus by-passed through the opening I64 and vents I62 to the atmosphere. In this manner the amount of heated air supplied to the compartment is reduced, it being apparent that a fresh air makeup for the by-passed air is readily obtained by opening theusual car window. The header is also connected by a conduit I66 with a defroster unit I1 I. As illustrated in Figs. 3 and 15, the defroster-is in continuous operation with operation of the heater..

'The invention provides further means for conditioning the fuel prior to its ignition in the heater so as to provide for a quiet and steady burning of the mixture in the combustion chamber. The chamber is of substantially cylindrical form and of relatively short length, but is constructed in a manner to have therein a plurality of connected longitudinally extending passages, with combustion of the mixture therein being progressive throughout the combined length of such passages.

This retention of an active flame within a combustion chamber of elongated construction provides for a relatively large heat radiatim: suroperation.

face immediately adjacent the combustion chamber so that the generated heat is utilized directly at its source. The volume of heated air admitted into the passenger compartment from the heater is readily varied by a control unit located for manual operation in the passenger compartment. The divisionof the heater unit into a mechanical compartment and into a combustion compartment provides further for a distinct isolation of the operating devices from the heat of the combustion chamber, and the utilization of the mechanical compartment as a part of the passage flow for the recirculated air through the heater unit, whereby to effect a continuous cooling of the mechanical devices during all times of heater It is to be understood that the relative temperature values used in the above description are representative for one kind of fuel and will vary for different kinds of fuel. Although only a preferred embodiment of the invention has been illustrated and described herein, it is to be understood also that the invention is not to be so limited, since alterations and modifications therein can be made which are within the full intended scope of the invention as defined by the appended claims. f

I claim 1. In a unit heater of internal combustion type for mobile craft having a-=battery and a space to be heated, the ,combination of a combustion chamber, an air circulating passage about said bustion chamber, means for supplying air to said combustion chamber, means for supplying fuel to said combustion chamber, means for conditioning said air and fuel prior to its ignition in said combustion chamber, with said conditioning means being arranged in said-one compartment, means for circulating air from said space about said combustion chamber, an electrical motor for operating said air'circulating and air supply means, with said motor, air supply means, circulating air means, and fuel supply means being located in the other of said compartments, the recirculated air from the space being passed through said other compartment prior to its cir- 'means -for supplying air to said combustion means in said space operatively connected with said by-pass valve to control the amount of air circulated into the space from about said combustion chamber, with said two electrical means, and the heating element and the ignition means being operated entirely by the electrical power from said battery.

2. In a mobile craft having a space therein and an engine with a battery therefor, a unit heater of internal combustion type having frame means and including in combination a combustion chamber, means for circulating air from said passenger compartment about said combustion chamber, a fuel conditioning unit in operative association with said combustion chamber, a. fuel supply, an electrically operated fuel pump for delivering fuel to said conditioning unit from said fuel supply, means for supplying air to said condltioning unit, an electrical motor common to said air circulating and said air supply means, electrical heating means in said conditioning unit,-w ith all of said defined means of said unit heater being operatively supported entirely on said frame means, and housing means for completely enclosing saidunit heater, with all of said electrical means being operated by the electrical power from said battery.

3. A heater of internal combustion type for a mobile craft having a space therein, including in combination frame means and an enclosing housing therefor, with said frame means including a wall portion dividing said housing into two compartments, a combustion chamber in one of said compartments, ignition means in said comchamber, means for supplying fuel to said combustion chamber, said fuel supply means being supported on the opposite side of said wall portion and located within the other of said compartments, means for conditioning said air and fuel prior to its passage into said combustion chamber, said conditioning means being arranged in said one compartment, means for ci'rculating air from said passenger compartment about said combustion chamber, a motor common to said air circulating and said air supply means mounted on the opposite side of said wall portion and within said other compartment, with said circulating air and air supply means being arranged in said one compartment but in fluid flow communication with said other compartment, the circulated air from said space being passed through said other compartment prior to its circulation about the combustion chamber.

5. In a vehicle havinga passenger compartment, the combination of a unit heater of internal combustion type mounted below said compartment, and including a combustion chamber, means for supplying air and fuel to said combustion chamber, housing means completely enclosing said unit, an air passage about said combustion chamber, means for connecting said air'passage at each end with said passenger compartment, means entirely within said housing means for circulating air through said air passage, means on said housing means for by-passing to the atmosphere a portion of the air passing. through said air passage, and means located within said passenger compartment-and operatively connected with said air by-pass means to regulate the amount of air entering the passe'n ger compartment from said housing means.

6. In a vehicle having a passenger compartment and a battery, the combination with a unit heater of internal combustion type mounted below said compartmentand including. a combustion chamber, of a control circuit for said heater including said battery and a normally open main switch, means for circulating air from said compartment about said combustion trol arm being located in said compartment and I having a pair of oppositely extending lateral portions, said two portions being concurrently movable on movement of said control arm, means for operatively connecting one of said portions with said by-pass means, theother of said portions being engageable with said main switch to directly control its operation, with movement of said control arm in one direction movingsaid other portion to close said switch and the continued movement of the control arm in said one direction moving said one portion to progressively reduce the amount of air which is by-passed from said heater.

- 7. In an automobile having a passenger compartment and a battery, the combination with a unit heater of internal combustion type operable entirely by the power from said battery and including a combustion chamber, of means including an operating lever for controlling the operation of said heater, said control means being located in said passenger compartment, a control circuit for said heater including said battery, means in said heater for circulating air from said passenger compartment about said combustion chamber, means for by-passing a portion of said circulated air from said heaterto the atmosphere, a housing for said control means having a slot in a wall portion thereof, means movably supporting one end of said operating lever in said housing, the opposite end of said lever extending through said slot-and being slidably movable therein, said operating lever having oppositely extending arms near said one end, a control switch in said control circuit mounted in said housing, means operatively connecting one of said arms with said by-pass.

of recirculated air by-passed from said heater, the control switch being open only when the regul-ating lever is at said one end of the slot.

8; In a heater of internal combustion type, the combination with an air and fuel mixing chamber of a fuel system for supplying fuel to said chamber including a pump having a pulsating discharge, a fuel injector mounted on said cham ber and having a discharge passage in fluid flow communication with said chamber and a fuel inlet, said discharge passage having a small diameter with reference to its length and said inlet being in fluid communication with said pump, said injector having acavity fuel reservoir therein between said discharge passage and inlet, with said reservoir being of a large volume relative to the volume of said discharge passage, said reservoir on operation of said fuel system having an air pocket therein which serves to cushion the discharge pulsations from said pump to provide for a substantially steady flow of fuel from said discharge passage into said chamber.

9. In a heater of internal combustion type, a combustion chamber having a body portion of substantially tubular shape, said body portion being integrally formed with angularly spaced fins extending radially from the periphery thereof, said fins being bent double with their inner ends opening into said chamber, a longitudinally extending partition member of substantially X-shape having end portions, said partition member being fitted within said body portion with corresponding opposite sides thereof arranged in the inner ends of corresponding oppositely disposed fins, and a cover portion for each end of the body portion, said end portions being open to provide for a continuous circuitous passage in said combustion chamber, with one of said cover portions having an aperture in register with said passage to provide an inlet thereto and an aperture in register with said passage to provide an outlet therefrom.

10. In a heater of internal combustiontype, a combustion chamber having a body member of substantially tubular shape with an axial bore therein, said body being of integral construction and having the periphery thereof alternately formed with arcuate portions and longitudinally extending radial fin elements, said fin elements being bent double and having their inner ends opening into said body member, means for dividing the bore of the body member into a plurality of interconnected axially extending passagesineluding a partition member positioned within said bore and extending axially of said body member, with the side portions of said partition member being positioned within the inner ends body member, with at least one of said cover p01- providing for a gradual decrease in the amount tions having apertures therein in communication with said interconnectedpassages.

11. In a heater of internal combustion type, th combination of an air and fuel mixing chamber and a combustion chamber having an inlet, said mixing chamber having an outlet arranged within said inlet, a plate extending over said outlet for insulating the mixing chamber from the heat of the combustion chamber, means for supplying air and fuel to said mixing chamber, a heating element arranged in said mixing chamber for vaporizing the fuel supplied thereto, said heating element having an igniting end portion extending through said heat insulating plate into said combustion chamber, a second heating element mounted in said plate and extending into said combustion chamber, said second heating element .being of substantially cylindrical form and having a free end of enlarged section, said enlarged section being arranged in substantial adjacence to said igniting end portion, with said plate having apertures formed near the peripheral portion thereof foradmitting the air and fuel mixture from said mixing chamber into the combustion chamber and into the efiective heating zones of said igniting end portion and second heating element, and means for adding supple- (ill ' the inlet of saidcombustion chamber, a heat ill-1' mentary air to said mixture after its passage about said second heating element.

'12. In a heat generator of internal combustion type, the combination of a combustion chamber having an inlet and an outlet, an air and fuel mixing unit having an outlet arranged within sulating. plate extending over said unit outlet but spaced inwardly therefrom to provide an axially extending annular rim at said outlet, said plate having apertures formed near the peripheral edge thereof, ignition means in said combustion chamber positioned substantially adjacent said annular rim, means for supplying air and fuel to said mixing unit, with the air and fuel mixture initially entering said combustion chamber from said unit being relatively rich, means for supplying secondary air at said combustion' chamber inlet and about said rim, said rim re- 13. A heater including a preassembled air and fuel mixing unit having aninlet at one end and an outlet at its opposite end, electrical means for supplying air and fuel to said unit at said inlet, a perforated heat insulating plate extending over said outlet, an electrical heating element extending through said unit,'- said heating element having a portion thereof extending outwardly from said unit at said one end; thermostatic means including a pair of bi-metallic switches mounted on said extending portion and responsive to the temperature condition of said heating element, one of said switches being arranged to control the operation of said heating element and the other of said switches being arranged to control the operation of said electrical air and fuel supply means, and means for re- 3 taining said thermostatic means on said extending portion.

14. In a heating unit of internal combustion type, the combination of a combustion chamber having an inlet with an air and fuel mixing unit 1 having one end in fluid flow communication with said inlet, said mixing unit having a rim portion' 1 at said one end extending into said combustion chamber inlet,.ignition means in said combustion chamber at said one end of the mixing unit, means for supplying air and fuel'to said mixing unit for burning in said combustion chamber,

' and means for supplying secondary air for burning in said combustion chamber, said secondary air being admitted into said combustion chamber from about said rim portion, with said rim portion retaining the secondary air away from the mixture leaving the mixing unit at said one end until after the ignition of said mixture b said ignition means. i

15. In a heating unit of internal combustion type, the combination with a combustion chamber having an inlet of an air and fuel mixing unit having one end in fluid communication with said inlet, said one end having a longitudinally extending rim portion thereon, perforate heat insulating means extending across said mixing unit at said one end, ignition means in said combustion chamber at said inlet spaced from said insua lating means in the direction of fluid flow in said combustion chamber, means for supplying air and fuel to said mixing unit for burning in said combustion chamber, and means for supplying supplementary air for burning in said combustion chamber from about said rim portion. with means including a walled portion influid-flow communication at one end part with the combustion portion of the heater and having a fuel and air introducingportion at another part to introduce air' and fuel adjacent one another into the walled portion, means for supplying heat to the walled portion to vaporize the fuel introduced therein and heat the air introduced therein, and apertured means at said one end part through which the mixture of vaporized fuel and heated air passes to the combustion portion.

17. In a heater of the internal combustion type in which combustion takes place at substantially atmospheric pressure, the combination including a combustion portion at substantially atmospheric pressure in which combustion is initiated at a position therein, means for conditioning the heater fuel for combustion, said means including a walled portion in fluid-flow communication at one end. part with said-combustion portion of the heater and having a fuel and air introducing portion at another part to introduce air and fuel adjacent one another into the walled portion, means for supplying heat to the walled portion to vaporize the fuel and heat the air introduced therein, and apertured means at said one end part through which the mixture of vaporized fuel and heated air passes to the combustion portion, and air ports for introducing air into the combustion portion beyond said position at which combustion is initiated to improve the combustion after said position.

18. In a heater of the internal combustion type, the combination including a combustion portion, an air supply portion separated therefrom, and means for conditioning the heater fuel for combustion including a walled portion havin; one end part extending into the combustion portion and in fluid-flow communication therewith and' another part extending into the air supply portion to be cooled by the air in said supply portion, said conditioning means including a fuel and air introducing portion to introduce fuel and air into the walled portion, and means for supplying heat to the conditioning means to vaporize the fuel introduced into the walled portion and heat the air therein and provide a vaporous mixture thereof, with said vaporous mixture passing to the combustionportion for combustion.

19. A heater of the internal combustion type including in combination an enclosing housing, and heater structure within the housing including a combustion portion extendingsubstantially longitudinally of the housing at one side thereof and having an inlet part at one end portion, an air supply portion extending along another side of said housing at said one end portion, including two air supplies with one of said air supplies being for passin over the outside of said combustion portion, and the other of said air supplies being in fluid-flow communication with the combustion portion, a fuel conditioning portion at said inlet part communicating with said combustion portion for receiving air from said other air supply and for receiving fuel, heating means, for vaporizing the fuel within said conditioning portion for passage as a vaporous mixture into said combustion portion, and fuel supply means within said housing having a portion along a further side of said housing with said further side extending substantiallylongitudinally relative to said one side for the combustion portion, with said fuel supply means supplying fuel to the conditioning portion.

20. A heater of the internal combustion type including in combination an enclosing housing,

and heater structure within said housing includ-- ing a combustion portion along one side of thehousing and having an inlet part, an electrically operated fuel pump and fan driving means along another side of the housing extending substantially longitudinally relative to the combustion portion and adjacent thereto, fan means driven by said driving means and a pair of air supply portions exposed thereto extending along a further side of the housing substantially at right angles to the first two mentioned sides, a fuel conditioning portion at said inlet part to receive fuel from said fuel pump and air from' one of said supply portions, means for vaporizing the fuel within the conditioning portion to provide a vaporous mixture with the air therein for said combustion portion, and with said other air supply portion supplying air over the outside of the I combustion portion.

21. A heater system of the internal combustion type having operating structure assembled substantially in an L-shape, said structure including in one leg portion of the substantially L-shape a longitudinally extending combustion portion having an inlet at one end, an air circulating portion on the outside of said combustion portion longitudinally thereof, a pair of air supply portions at said one end of said combustion portion, with one of said air supply portions in fluid-flow communication with said air circulating portion, and the other air supply portion in fluid-flow communication with said combustion portion, fuel vaporizing means in said other air supply portion having a fuel and airinlet part and an outlet part comunicating with said combustion portion inlet, with heating means for heating said vaporizing means to vaporize the fuel therein, air moving means having at least a portion thereof in the other leg portion of the substantially L-shape communicat ing with both air supply portions to supply air thereto for combustion and circulating purposes, and housing means enclosing said operating structure. r l

22. In a heater of the internal combustion type including a combustion portion, a combustion air supply portion separated therefrom but in fluidflow communication therewith, and means for conditioning the heater fuel for combustion including a walled portion having an outlet part in fluid-flow communication with the combustion portion and another partexposed to the air in the air supply portion for cooling the walled portion at said another part, said 'walled portion having air and fuel supplied thereto, and means for supplying heat to the conditioning means to vaporize the fuel therein and heat the air and provide a vaporous mixture thereof, with said,

aasassa from each of two adjacent fins to form a longitudinally extending wall for the combustion portion, and means dividing said combustion chamber into a plurality of passages including apartition wall having a portion on each of two sides extending within a corresponding fin at the inside thereof, said partition wall being retained in said body by contact with the walls of said cor-' responding fins.

24. In a heater having a fuel supply and an air supply and a combustion portion with the latter operating at low pressure, the combination with means for conditioning the fuel for combustion of thermal operated means for controlling the fuel feed, said conditioning means includinga walled portion for receiving fuel from the fuel supply. and in fluid-flow communication at an. outlet end with the combustion portion, heating means for heating the walled portion for vaporizing the fuel introduced therein, said heating means having a portion extending outwardly from the walled portion, and said thermal operated means including a portion movable responsive to the heat in the heating means and acting upon movement to control the fuel feed to the walled portion.

25. A heat exchange unit including a one piece body member originally provided in flat sheet form and formed to a tubular structure having a bore extending axially thereof, said body having the periphery thereof integrally formed with spaced longitudinally extending but laterally projecting fin portions, said fin portions being bent double with their inner ends opening into said bore, and means dividing said bore into a plurality 'of longitudinal passages including a partition means having longitudinal side portions receivable withinthe inner ends of corresponding fin portions to retain said partition means in said body member.

26. A heat exchange unit having a body member with "a longitudinal bore extending therethrough;- said body member being integrally formed with a plurality of spaced radial extensions, each of said extensions having opposite wall portions joined at the outer end and open finincluding. a pair of oppositely disposed walls joinedin an integral'longitudinal edge at the outside thereof and being separable at the inside thereof, a plurality of combustion portion wall parts, each part'being integral with one fin wall at the inner end thereof so that the space within a radial extension is open to said longitudinal bore, and'partition means for defining a plurality of chambers in said body member having portions extending within certain of said radial extensions at the inner ends thereof, with the wall portions of said certain radial extensions. retaining said able within said body member through said oneend thereof and having a perforated portion engageable with said stop portion to define an .air and fuel mixing chamber within said unit at said opposite end, and a perforated wall por-- tion positioned transversely of said body member intermediate said open end and said cup-shaped member, with said perforated wall portion and perforated portion defining an equalizing chamber substantially within the confines of said cupshaped member, and heating means positioned longitudinally within said body member for ing the same.

28. A preassembled liquid fuel vaporizing unit having a substantially closed end and an open heatreceivable within said housing member through the open end thereof, said insert having a perforated portion spaced from the substantially closed end of said housing member, with said perforated portion and the substantially closed housing end defining said mixing chamber, perforated wall means intermediate the perforated portion of said insert and said open end extending transversely of said housing member, with said wall means and perforated portion defining said equalizing chamber, and heating means extending longitudinally of said housing member for heating the same;

29. In a heater having an internal combustion portion with an inlet, the combination of means preparing a liquid fuel for burning including a first-region with air and fuel being fed into said first region adjacent one another, an air supply to the first regionfor creating turbulence in the fuel and air in the first region to mix them, a second region for the mixture wherein the turbulence is lessened and the mixture made substantially uniform throughout, and means acting on both regions for heating the fuel and air in said both regions to condition the fuel and the. mix ture, said mixture passing at the inlet into said combustion portion to be ignited.

30. In a heater of the internal combustion type, the combination including a combustion portion, a fuel conditioning portion opening into the combustion portion having fuel and air introduced therein a fiacent one another, a region within the conditioning portion adjacent the place of introduction, with the fuel and air being intermixed in said region substantially in a turbulent state, said conditioning portion having a region adjacent the outlet thereof to the combustion portion wherein the mixture is smoothed out and a rich mixture of fuel and air isobtained to pass into the combustion portion to be ignited, and means acting on both regions for heating the mixture in said both regions, and air inlets for introducing additional air into the combustion portion beyond the point of initial combustion and provide progressive combustion beyond said point.

31. In a heat generator of internal combustion type the combination of a plurality of portions including an air supply portion having air moving means therein, a combustion portion, and an air and-fuel conditioning portion having one part in communication with the air supply portion and receiving air therefrom, with fuel introduced at said one part, and said air moving means providing for turbulence in the air and fuel to improve the mixing thereof, and said air and fuel conditioning portion having another part communicating with the combustion portion with mixing and conditioning being substantially completed therein, and means providing heat at said air and fuel condition portion to heat the air and vaporize the fuel in both parts therein.

HARRY B. HOLTHOUSE. 

